Ladder rack

ABSTRACT

A rack to hold an elongated article such as a ladder on a vehicle. The rack includes guides in the form of a plurality of coplanar horizontal rollers and spaced apart vertical rollers which facilitate loading even heavy ladders on the rack. The ladder is held securely in position against both vertical and horizontal movement by clamping arms each having ends curved to conform to the curvature of the rungs of a ladder mounted on the rack. The arms are spaced from each other and are pivoted simultaneously by a linkage which assures that the arms each engage a rung and clamp the ladder between the arms. The curved ends of the arms extend over the rungs they engage to prevent vertical movement of the ladder.

United States Patent [1 Payne 1 1 LADDER RACK [76} Inventor: Earl E. Payne, R.D. No. 2, Box 91,

Blairsville, Pa. 15717 Notice: The portion of the term of this patent subsequent to Sept. 1, 1987, has been disclaimed.

[22] Filed: Feb. 12, 1968 [21] Appl. No.1 704,629

[52] 11.8. CI. 224/421; 224/4238; 248/361; 214/84 [51] Int. Cl. 860: 9/04 [58] ield of Search 214/450; 224/421, 42.1 D, 224/421 LM:42.1 F, 42.19, 42.38, 42.4, 29; 248/361 [56] Relerences Cited UNITED STATES PATENTS 1,360,412 11/1920 Kirchner 214/3840 UX 1,417,223 5/1922 Anderson 224/38 1,554,957 9/1925 Engle 224/4219 1.991.900 2/1935 Larsen 224/421 X 2,237,853 4/1941 Troche 224142.43 X

i Q 55 8 U 5 1*June 10, 1975 2,247,128 6/1941 Levey 224/421 LM X 2,615,667 10/1952 Smith et a1 224/29 X 2,812,087 11/1957 Zoller 214/450 FOREIGN PATENTS OR APPLICATIONS 800,941 12/1950 Germany 248/361 Primary Examiner-Gerald M. Forlenza [57] ABSTRACT A rack to hold an elongated article such as a ladder on a vehicle. The rack includes guides in the form of a plurality of coplanar horizontal rollers and spaced apart vertical rollers which facilitate loading even heavy ladders on the rack. The ladder is held securely in position against both vertical and horizontal movement by clamping arms each having ends curved to conform to the curvature of the rungs of a ladder mounted on the rack. The arms are spaced from each other and are pivoted simultaneously by a linkage which assures that the arms each engage a rung and clamp the ladder between the arms. The curved ends of the arms extend over the rungs they engage to prevent vertical movement of the ladder.

9 Claims, No Drawings SHEET PATENTEDJUN 10 I975 FARL E. BAY/v5 M/FWW we,

I iORNEYS kuaw PATENTEDJUN 10 I915 INVENTOR EARL E. PAYNE Z ORNEYS 1 LADDER RACK This invention relates generally to a rack for carrying an elongated article on a vehicle and specifically to a rack mounted on the roof of a vehicle and on which an elongated ladder can readily be placed and secured to the vehicle against loss during normal movement of the vehicle.

More specifically, this invention relates to a vehicle mounted rack for securely holding ladders of the extension type on the vehicle, the rack functioning not only to hold the ladder on the rack but also to hold the several sections of an extensible ladder in tight engage ment with each other whereby the rattling that normally occurs with presently known racks is eliminated.

While racks of various types are known in the prior art to mount ladders, some of the extensible and some of the single section type, such prior art racks have not proven to be completely satisfactory. In many instances, these prior racks either loosely clamp the ladder on the rack whereby the ladder is not completely restrained and can move slightly thus causing damage to the ladder or to the rack during normal movement of the vehicle, not to mention the annoying rattle which occurs when the ladder is not completely restrained. With other prior racks, whe e the ladder is securely held, the hold-down or tie-down devices are usually so cumbersome and time consuming to operate that frequently only one or two of the many provided are used with corresponding unsatisfactory results. Where all the hold-down or tie-down devices are used the time consumed is usually deemed excessive and hence, these racks are also unsatisfactory.

Another consideration for a ladder rack is the ease with which the ladder can be placed on the rack. Where racks are mounted on the roof of a vehicle, as is the case with the ladder rack of this invention, it is frequently difficult for one person to load the ladder on the rack. The ladder racks of the prior art have resorted to quite complicated pivots and linkages to facilitate such loading. In the ladder rack of this invention, loading is facilitated in a unique manner which permits a single workman to readily load the ladder on the rack without excessive exertion and without danger of damage to the ladder, the rack, or the vehicle on which the ladder is loaded.

In addition, the ladder rack of this invention utilizes a unique clamp arrangement which secures the ladder on the rack by merely moving a single lever a short distance. The lever is readily fixed in this secured or latched position of the hold-down devices and provision is made to lock the lever to prevent unauthorized removal of a ladder from the rack. The unauthorized removal feature does, of course, prevent theft of the ladder where the vehicle on which the rack and ladder are mounted is unattended or parked in an unguarded area.

Correspondingly, an object of this invention is to provide an article holding rack for elongated articles which facilitates loading an article on the rack and removing the article from the rack.

Another object is a rack for holding an elongated ladder on the roof of a vehicle, the rack including clamping means to securely hold the ladder in position on the rack.

Another object is a rack having an improved loading arrangement which facilitates loading and unloading the ladder from the rack without the need for several workmen to accomplish same.

Still another object is a ladder rack for holding a ladder on the roof of a vehicle, the ladder rack being so arranged and disposed that a ladder can readily be moved into position on the rack and securely clamped to the rack from a common end of the vehicle by a single workman, and which has provision to prevent unauthorized removal of the ladder from the rack.

Yet another and significant object is a ladder rack which is durable, inexpensive to manufacture, and which can be used with ladders of various types. yet is reliable and makes the previously laborious task of loading a ladder on a vehicle a simple one man operation.

In order that the manner in which the foregoing and other objects attained in accordance with this invention can be understood in detail, particularly advantageous embodiments thereof will be described with reference to the accompanying drawings, which form a part of this specification and wherein:

FIG. 1 is a top plan view of the rack with a ladder partially shown thereon in phantom lines and with the several parts of the rack in a clamping position;

FIG. 2 is a side elevational view of the rack mounted on the roof of a vehicle, with the rack in a ladder clamping position;

FIG. 3 is a left-hand end elevational view of the rack of FIGS. 1 and 2 with the ladder thereon shown in phantom lines;

FIG. 4 is an enlarged partial view showing the details of a clamping arm;

FIG. 5 is a sectional view taken along lines 5-5 of FIG. I; and

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 1.

Referring now to the drawings in detail and particularly to FIGS. 1 and 2 there is shown an elongated object or article carrier in the form of a ladder rack I mounted on and secured to the roof 2 of a vehicle. While the details of the vehicle are not shown, it is to be understood that the ladder rack has particular utility for holding ladders used for telephone servicing, and thus the vehicle may be a panel truck of the type used by telephone service men. Ladder rack 1 includes a generally rectangular frame 3 having elongated side rails 4 and 5, of L-shaped cross-section which are spaced apart and parallel to each other. Side rails 4 and 5 each have a vertical leg 6 and a horizontal leg 7 (FIG. 3). The side rails are so arranged that horizontal legs 7 project inwardly of the sides of the ladder rack. Side rails 4 and 5 are joined together by a plurality of spaced apart parallel cross members 8-12. Each of the cross members takes the form of a flat elongated metal strap. As shown at FIGS. 1 and 5, with reference to cross member 10, the cross member extends perpendicularly between side rails 4 and 5 and lies on the upper surface of horizontal legs 7 of the side rails. The cross members are fixed to the side rails by welding as at 13. Side rails 8 and 12 extend respectively along the opposite ends of the rack and are secured to the side rails in the same manner as cross member 9. Cross member 11 is positioned approximately midway between cross members 8 and 12 so it extends transversely of the rack approximately at the center of the rack.

With reference to FIG. 1, it is apparent that side rails 4 and 5 cooperate with cross members 8-12 to provide a frame 3 which is generally box-shaped and elongated in a direction along the length of the side rails. Guide roller assemblies 14-17 are connected one at each of the corners of frame 3 and project upwardly above the rails of the frame. Roller assembly 14 (FIG. 3) includes an upright member 18 of L-shape as viewed in section. having a leg 19 which lies against and is secured to leg 6 of rail 4 as by welding. Leg 20 of angle 18 projects outwardly from rail 4. Roller support plates 21 and 22 project horizontally from the outer surface of leg 20 in spaced apart parallel relation to each other. Support plates 21 and 22 have openings formed therein to receive a shaft 23 on which a vertical guide roller 24 is journaled. Advantageously, shaft 23 is maintained in position between plates 21 and 22 by cotter pins 25 which are readily removed to facilitate replacement of roller 24 if it is worn or otherwise damaged. Roller assembly 16 is identical to roller assembly 14 and is merely roller assembly 14 rotated 180 in a horizontal plane and fixed to the diagonally opposite end of rack 1.

Roller assembly 15 is similar to roller assembly 14 and includes an upright support member 26 having its lower end fixed to leg 6 of side rail by welding a leg 27 to leg 6. Leg 28 extends outwardly of frame 3 and has connected thereto a pair of spaced apart roller supporting plates 29 and 30. A shaft 31 on which a guide roller 32 is journaled extends through openings in plates 29 and 30, shaft 31 being removably retained by cotter pins 33 passing through the ends of the shaft. Roller assembly 17 is identical to roller assembly and is merely roller assembly 15 rotated 180 in a horizontal plane and again connected to the diagonally op posite end of the frame.

As shown in FIG. 1, roller assemblies 14-l7 mount their respective rollers so that each roller is rotatable about a vertical axis, and the rollers of roller assemblies 14 and 15 project outwardly beyond cross member 8 at one end of the rack and the rollers of roller assembly 16 and 17 project outwardly beyond cross member 12 at the other end of the rack. The spacing between the rollers of roller assemblies 14 and 15 is identical to the spacing between the rollers of roller assemblies 16 and 17 and this spacing is slightly greater than the width of a ladder 34 which is to be mounted onto the rack in a manner which will subsequently be described in detail.

Ladder rack 1 also has horizonal roller assemblies 3537. Roller assembly 35 includes a pair of rollers 38 and 39 mounted on a shaft 40 and maintained in spaced apart relation by a spacer tube 40. Roller assembly 35 is vertically above cross member 8, and shaft 40 has its ends inserted through aligned bores in legs 19 and 27, respectively, of guide roller assemblies 14 and 15. Shaft 40 is secured against axial movement by cotter pins.

At the opposite end or rack l, roller assembly 37 is mounted immediately above cross member 12. Roller assembly 37 includes rollers 41 and 42 mounted on a shaft 43 and maintained in spaced part relation to each other by a spacer tube 44. Shaft 43 extends through suitable openings in the legs of the upright angles of vertical roller assembly 16 and 17 in the same manner as described for shaft 40 of horizontal roller assembly 35.

Immediately above cross member 11 at the center rack l is roller assembly 36 which includes rollers 45 and 46 mounted for rotation on horizontal shaft 47 and maintained spaced apart by spacer tube 48. The ends of shaft 47 are received in aligned openings respectively in a pair of vertical strap members 49 and 50 connected to side rails 4 and 5 and in alignment with cross member 11. Horizontal rollers 38, 39, 41, 42, 45 and 46 are all of the same diameter and the roller assemblies 35-37 are so mounted that the axes of the several rollers are parallel to each other and are in a common horizontal plane spaced above frame 3. Correspondingly. the vertically uppermost surfaces of each roller are tangent to the same horizontal plane.

As shown at FIGS. 13, ladder 34 which is adapted to be supported by rack I is of the two-section extensible type and includes a first or lower section 51 (FIG. 3) slidable relative to a second or upper section 52. Section 51 has side rails 53 and 54, each side rails being formed with a groove 55 to receive the side edge 56 of the side rails 57 of upper section 52. Thus, section 52 is slidably connected to section 51 and can move longitudinally relative to section 51. However. vertical movement either up or down, with the sections in the position of FIG. 3, is prevented by the interengagement of edges 56 in grooves 55.

As shown at FIG. 3, the distance between rollers 24 and 32 of vertical roller assemblies 14 and 15 is sub' stantially the same as the distance between the outer edges of side rails 53 and 54 of lower section 51 of the ladder. Also, rollers 24 and 32 each have a height slightly greater than the height of side rails 53 and 54 as measured vertically. The rollers of vertical roller assemblies 16 and 17 are each the same length as rollers 24 and 32 and the several rollers have their upper ends aligned in the same horizontal plane and their lower ends aligned in the same horizontal plane. Thus, the relationship shown at FIG. 3 is the same for roller assemblies l6 and 17 at the opposite end of the rack. It will also be noted that horizontal roller assemblies 35-37 are so mounted that the uppermost surface of each roller such as surfaces 59 and 60 of rollers 38 and 39 are slightly above the bottom ends of each of the vertical rollers. Thus, bottom surfaces 60 and 61 of the respective side rails 53 and 54 of the ladder are always maintained above lower end surfaces 62 and 63 of the several vertical rollers. As previously mentioned, the several vertical rollers have a length greater than the height of side rails 53 and 54 of the ladder and, thus, the upper ends of rails 53 and 54 are below the upper ends of the vertical rollers.

Ladder 34 is securely held on the rack by a clamp or holddown assembly 65. Clamp assembly 65 includes an actuating lever 66 adjacent one end of the rack, a linkage assembly 67 including a force transmitting member 68 and force transmitting rods 69-71, and clamp arm assemblies 72 and 63. As shown at FIG. 1 and 4, arm assembly 72 includes an elongated shaft 74 which is perpendicular to and extends through aligned openings in vertical legs 6 of side rails 4 and 5. The shaft is prevented from endwise movement by cotter pins 75 at each end of the shaft. Iournaled on shaft 74 is a sleeve 76 that spans the distance between the vertical legs 6 of the side rails. Fixed to sleeve 76 is a clamp arm 77 which is advantageously secured to the sleeve by weld ing as at 78. As shown at FIG. 1, clamp arm 77 is fixed to the sleeve at a location offset to one side of the longitudinal center line of frame 3. Clamp arm 77 is clongated and has an arcuately curved outer end 79 with an inner surface 80 of the same curvature as a stop portion or rung 81 of ladder 34. End 79 extends arcuately ssssssis and terminates at a tip 82. Fixed to arm 77 at a location below bottom surface 6l,of rail 54 of the ladder (when the arm is upright as shown at FIG. 4) is,a connector tab 83 with an opening therein to receive the bent end 84 of rod 71. The rod is held in the tab by a cotter pin 85. End 84 is a loose fit in the opening of tab 83 to provide a pivot connection between rod 71 and the tab.

Clamp arm assembly 73 is identical to arm assembly 72 and is merely arm assembly 73 turned Hit) in a horizontal plane. Here, clamp arm 86 is mounted on sleeve 88 which is journaled on shaft 89, the clamp arm 86 being offset toward the other side of the longitudinal center of the rack the same distance that arm 77 is.offset from the longitudinal center line in the opposite direction. Sleeve 88 is journaled on a shaft 89 which is connected to leg 6 of side rails 4 and 5 in the same manner as shaft 74. i r. 1

Rod 70 has abent end 90 which extends through an opening in tab 91 fixed to clamp arm 86. Tab 91 is like tab 83 and end 90 of rod 70 is pivotally connected at the tab. I i

As shown at FIGS. 1 and 5, member 58 is pivotally connected to the center of cross member 10. The pivotal connection includes a bolt 92 which extends vertically through the center of member 68 and is secured by a nut 93. An elevating boss 94 between member 68 and cross member elevates member 68 above the cross member to provide clearance for the ends of the several rods that are connected to the member. As shown at FIG. 1, member 68 has two'openings on the same side of the pivot provided by bolt 92 and which receives respectively ends 95 and 96 of rods 69 and 70. These openings are the same distance from the axis of bolt 92 as an opening at the opposite end of the member into which downwardly bent end 97 of rod 71 extends. Ends 95-97 of the several rods are pivotail'y eonnected to member 68 by a relatively loose fit between the ends and the openings in the member to allow for.

some angular movement of the ends relative to the member. 7

Thus, with reference to FIGS. 1 and 2 and 4, it is evident that rod 70 is pivotally connectedat one end to member 68 and at its other end to clamparm 86. Rod 70 is pivotally connected at one end to member 68 and at its other end to clamp arm 77. When member 68 is rotated, clamp arms 77 and 86 each move in unison in opposite directions. With member 68 in the position i shown in FIGS. 1 and 2, clamp arms 77 and 86 are each generally vertical. However, if member or arm 68 is rotated clockwise, then arm 77 pivots downwardlyto the position shown for arm 77, at. FIG. 4. Simultaneously, arm 87 is pivoted downwardly in an opposite direction to a like position beneath bottom surface .61 the side rail of ladder 34. 1

Such clockwise rotation of arm 68 occurs upon manipulation of lever 66 in a counterclockwise direction. As shown at FIG. I, lever 66 has an elongated operating arm 98 and a leg 99 projecting perpendiculariy from the arm. End 100 of leg 99 is bent upwardly and outwardly so it lies in plane spaced above the leg and the cross member. Lever 66 is pivotallymonnected to I cross member 9 by a U-shaped bracket 101 fixed. to the cross member, and a pin or bolt 102 which extends through aligned openings in the cross member, bracket,

and lever 66. End 100 of arm 66 is pivetaily connected to bent end 103 of rod 69. Rod 69 is provided with a turnbuckle 104 which facilitates adjusting the length of the rod.'

As shown in FIGS. 1 and 2, a lock plate 105 is located immediately beneath arm 98 of lever 66. This lock plate is provided with an opening 106 which aligns with an openirig 107 in arm 98 when the lever is moved to the locked position of FIG. 1. To prevent unauthorized removal ofa ladder placed on the rack. it is merely necessary to place a padlock 108 through these openings. whereupon the lever 66 and ladder 34 are locked against removal.

Rack 1 is mounted on roof 2 of a vehicle as shown at FIG. 2, with lever 66 adjacent the rear of the vehicle. The mounting includes several support rails 109 which each have a length at least as wide as frame 3 and extend transversely across roof 2 of the vehicle. Support rails 109 are spaced apart and preferably parallel, and bolts 110 extending through the horizontal legs 7 of the side rails secure the rack to the members.

Where rack l is to be permanently fixed to the vehicle, screws or other fasteners may be used to fix support rails 109 to the roof of the vehicle. If it is desired that the rack be removable, connector straps 111 with hook-shaped ends 112 are advantageously used to se cure the cross members and, hence. the rack to the roof of the vehicle. The hook-shaped ends 112 engage over the usual drain gutter which extends around the top of the vehicle and holds the rack in place. Similar straps lll with hook-shaped ends 112 can be used at the rear of the frame, as shown at FIG. 2.

OPERATION AND USE When it is desired to load a ladder onto the ladder .rack; operating arm 98 of lever 66 is first moved in a counter-clockwise direction as viewed at FIG. 1 which correspondingly moves leg 99 of the lever counterclockwise and exerts a push on rod 69 which causes member 68 to rotate clockwise thereby exerting a push on rods 70 and 71. By virtue of the connection between rod 70 and clamp arm 86, the clamp arm is moved pivotally in a clockwise direction to the phantom line retracted position of FIG. 2. Simultaneously, rod 71 exerts a push on clamp arm 77 which causes this arm to pivot in a counterclockwise direction to the retracted phantom line position shown at FIG. 2.

To load a ladder onto rack 1 the ladder is first positioned adjacent the rear of the vehicle with the lower end of the ladder a short distance from the vehicle so the-ladder extends toward the rear of rack 3 at an angle. The ladder is then positioned so the side rails of the ladder extend between vertical guide rollers 24 and 32.

Next, the lower end of the ladder is lifted whereupon the lower surfaces and 61 of the respective side rails of the lower section of the ladder engage support rol lers 38 and 39. Next, the lower end of the ladder is lifted and the ladder is pushed longtudinally, which is readily accomplished by a single workman since the support rollers rotate to allow the ladder to be easily pushed into position on the rack. When the midpoint of the ladder passes over rollers 38 and 39, the ladder tends to assume a horizontal position from which the ladder can be readily pushed into the position shown at FIG, 1, wherein the end 114 of the ladder is between roller assemblies 16 and 17 (adjacent the front of the rack) and the ladder is then in position to be locked to the rack.

The ladder is locked to the rack by moving lever 66 in a clockwise direction to the lock position of FIG. 1. Such movement of the lever exerts a pull on rod 69 which causes member 68 to rotate in a counterclockwise direction. Such movement of member 68 causes rods 70 and 7] to pull on and pivot arms 86 and 77 respectively from the retracted position (shown in phantom lines at FIG. 2) to the extended or ladder securing position of FIGS. 1, 2 and 4.

With the arms in the lock or ladder holding position. arm 77 is upright and exerts a force to the right toward the front of the rack on rung 81 of the upper section of the ladder as well as on rung 115 of the lower section of the ladder. Arm 86, however, exerts a force to the left or toward the rear of the vehicle on rung 6 of the upper section of the ladder as well as on rung 1 17 of the lower section of the ladder. Thus, the ladder is tightly clamped between arms 77 and 86 is fixed against longitudinal movement, and the upper section 52 is fixed against movement relative to the lower section In addition, curved tips 79 and 87 engage respectively over rungs 8] and 87 and thus, exert a slight downward force which holds the upper section of the ladder snugly against the lower section and correspondingly urges the lower section against the horizontal rollers 38, 39, 45, 46, 41 and 42.

Movement of the arms 77 and 86 to the ladder securing position also serves to align the rungs of the ladder vertically because of the forces exerted by the arms. It will be observed with reference to FIG. 2 that clamp arms 77 and 86, when in the upright or locking position shown are spaced apart a distance equal to the distance between the centers of the rungs engaged by the arms plus the diameter of a rung. In the preferred embodiment six rungs are between the arms, when upright. Since the distance between rungs of a standard ladder is 12 inches, the distance between arms is advantageously 60 inches plus the diameter of a rung. Each arm is somewhat shorter than the distance between adjacent rungs.

Advantageously, force transmitting rods 69-71 all act in tension during movement of the arms from the retracted to the upright or ladder securing position of the clamp arms. Thus, the ladder is secured by the clamp arms and held so long as lever 66 remains in the lock position of FIG. 1. Padlock 108, fixes lever 66 in the lock position when the shakel of the padlock is passed through the aligned openings 106 and 107 of the lock plate and arm respectively. With the padlock secured, unauthorized removal of the ladder is prevented.

To release ladder 34 from the rack padlock 108 is first removed whereupon lever 66 is again free to be pivoted manually. Arm 98 of lever 66 is moved counterclockwise, from the position of H6. 1 which, in turn, rotates member 68 clockwise via leg 99 of the lever and connecting rod 69. Clockwise movement of arm 68 pivots arm 86 downwardly because of the action of rod 70, and arm 77 also pivots downwardly simultaneously because of the action of rod 71. When arms 77 and 86 are pivoted to the retracted phantom line position which is below the rungs on lower section 51 of the ladder, the ladder is completely free to be removed from the rack. Thus, a workman need only grasp end 118 of the ladder and pull the ladder rearwardly off the rack. This is a simple matter because the several horizontal rollers allow the ladder to readily roll rearwardly when pulled. If the ladder is quite heavy, it is still easy for one man to handle by pulling the ladder to a position where only a short portion remains in engagement with rollers 38 and 39 of horizontal roller assembly 35 and then lowering the free end of the ladder. Then, the ladder can be pivoted outwardly away from the truck, being temporarily supported by rollers 38 and 39 while the free end is lowered.

It will be noted with reference to FIGS. 2 and 4 that ends 79 and 87 of the clamp arms are preferably rounded somewhat to slip easily across the several top rungs 81 and 116 which they engage respectively. Thus, the ends of the arms exert a downward force which urges the ladder tightly against the several sets of horizontal rollers and holds the ladder against movement either upwardly or longitudinally. Since the vertical rollers are closely adjacent the side rails of the lower section of the ladder, any tendency for the ladder to move transversely is effectively resisted. Since all the rollers are formed of rubber or some other resilient material the ladder is resiliently held in position by virtue of the resiliency of these rollers.

While a preferred embodiment of the articlesupporting device of this invention has been shown and described as used with a ladder, it is to be understood that the rack has utility for carrying objects and articles other than ladders and the use of the rack to carry such other articles is within the contemplated scope of this invention.

What is claimed is:

l. A roof rack for a vehicle to support and retain a ladder having side rails and rungs on the vehicle during normal travel of the vehicle comprising, in combination an elongated frame comprising spaced apart side members, and cross members extending between and secured to said side members;

means securing the frame on the roof of a vehicle;

a plurality of support rollers means mounting said rollers on said frame for rotation about axes spaced apart longitudinally of said frame, whereby a ladder on said rack engages said support rollers and is supported in spaced relation to the roof of the vehicle;

clamp means to secure a ladder to said frame, said clamp means being connected to said frame and including a first arm and a second arm,

said arms each having an arcuately curved ladder rung engaging portion;

mounting means mounting said first and second arms for pivotal movement in opposite directions about spaced apart axes,

to a first position in which said rung engaging portions are between a ladder on the rack and the roof of the vehicle, and

to a second position in which said arms extend between rungs of the ladder and said curved portions each engage a different rung of the ladder and exert force on the rungs to urge the ladder toward the support rollers,

a lever;

means mounting said lever on said frame at a location readily accessible for manipulation by a person adjacent the vehicle; and

linkage means interconnecting said lever and laid first and second arms, said linkage means connecting said arms for simultaneous movement, one toward the other, during manipulation of said lever to move said arms from said first to said second positions. 2. A rack according to claim I wherein said linkage means comprises a crank pivotally mounted on said frame. a first link connected to one of said arms and to said crank at one side of the pivoted mount of the crank, a second link connected to the other of said arms and to said crank at the other side of the pivoted mount of the crank, and a third link connected to said crank and to said lever to transmit motion of said lever to said arms via said crank and first and second links. 3. A rack to support and retain a ladder having side rails and steps on a vehicle during normal movement of the vehicle comprising, in combination an elongated frame; means securing the frame to the vehicle; support means carried by said frame, extending between a ladder loaded on the rack and the vehicle, and engaging at least the rails of the ladder, said support means preventing movement of said ladder in at least one direction; clamp means connected to said frame to secure said ladder to the rack, said clamp means including a first arm and a second arm; mounting means mounting said first and second arms for pivotal movement to a first position in which said arms are spaced from a ladder on said support means, are retracted, and lie between the support means and the vehicle, and

to a second position in which each of said arms engages a different step of a ladder on said support means and holds the ladder against the support means; and arm moving means on said frame to simultaneously move said arms from said first positions to said second positions; said arm moving means moving said first arm and second arm pivotally toward each other during movement from said first to said second positions. 4. A rack to support and retain a ladder having side rails and steps on a vehicle during normal movement of the vehicle comprising. in combination an elongated frame; means securing the frame to the vehicle; support means carried by said frame and engaging at least the rails of a ladder loaded on the rack, said support means preventing movement of said ladder in at least one direction; clamp means connected to said frame to secure said ladder to the rack, said clamp means including a first arm and a second arm; mounting means mounting said first and second arms for pivotal movement to a first position in which said arms are spaced from a ladder on said support means, and

to a second position in which each of said arms engages a different step of a ladder on said support means and holds the ladder against the support means;

arm moving means on said frame to simultaneously move said arms from said first positions to said second positions;

said arm moving means moving said first arm pivotally in one direction, and said second arm pivotally in a direction opposite to said one direction during movement from said first to said second positions; and wherein the steps of the ladder to be carried by the rack are rungs of arcuate curvature;

said arms each have an arcuately curved portion spaced from the location where the arms are pivotally mounted; and

said arcuately curved portions of said arms respectively engage spaced apart rungs of the ladder, with said arms in said second position.

5. A roof rack for a vehicle to support and retain a ladder having side rails and rungs of arcuate curvature on the vehicle during normal travel of the vehicle comprising, in combination an elongated frame comprising spaced apart side members, and cross members extending between and secured to said side members; means securing the frame on the roof of a vehicle; a plurality of resilient support rollers; means mounting said resilient rollers on said frame in coplanar relation for rotation about axes spaced apart longitudinally of said frame, whereby a ladder on said rack engages said rollers and is supported in spaced relation to the roof of the vehicle;

clamp means to secure a ladder to said frame, said clamp means being connected to said frame and including a first arm and a second arm,

said arms each having an arcuately curved ladder rung engaging portion;

mounting means mounting said first and second arms for pivotal movement in opposite directions about spaced apart axes parallel to the length of the rungs of a ladder on the rack,

to a first position in which said rung engaging portions are between a ladder on the rack and the roof of the vehicle, and

to a second position in which said arms extend between rungs of the ladder and said curved portions each engage a different rung of the ladder and exert force on the rungs to urge the ladder toward the resilient support rollers;

lever means;

means mounting said lever means on said frame at a location readily accessible for manipulation by a person adjacent the vehicle; and

linkage means connecting said lever means and said first and second arms,

said lever means being operable, upon manual manipulation, to move said arms toward each other during movement from said first to said second positions.

6. A rack according to claim 5 wherein said rack further includes lock means to lock said first and second arms in said second position to prevent unauthorized removal of a ladder from said rack.

7. A rack according to claim 6 wherein said lock means prevents movement of said lever means.

8. A rack according to claim 4 wherein said support means comprise a plurality of resilient rollers. 9. A rack according to claim 4 wherein said rack further includes guide rollers having axes of rotation generally normal to the plane of a ladder on the rack, and spaced apart longitudinally of said frame; said guide rollers facilitating the positioning of a 

1. A roof rack for a vehicle to support and retain a ladder having side rails and rungs on the vehicle during normal travel of the vehicle comprising, in combination an elongated frame comprising spaced apart side members, and cross members extending between and secured to said side members; means securing the frame on the roof of a vehicle; a plurality of support rollers means mounting said rollers on said frame for rotation about axes spaced apart longitudinally of said frame, whereby a ladder on said rack engages said support rollers and is supported in spaced relation to the roof of the vehicle; clamp means to secure a ladder to said frame, said clamp means being connected to said frame and including a first arm and a second arm, said arms each having an arcuately curved ladder rung engaging portion; mounting means mounting said first and second arms for pivotal movement in opposite directions aBout spaced apart axes, to a first position in which said rung engaging portions are between a ladder on the rack and the roof of the vehicle, and to a second position in which said arms extend between rungs of the ladder and said curved portions each engage a different rung of the ladder and exert force on the rungs to urge the ladder toward the support rollers; a lever; means mounting said lever on said frame at a location readily accessible for manipulation by a person adjacent the vehicle; and linkage means interconnecting said lever and said first and second arms, said linkage means connecting said arms for simultaneous movement, one toward the other, during manipulation of said lever to move said arms from said first to said second positions.
 2. A rack according to claim 1 wherein said linkage means comprises a crank pivotally mounted on said frame, a first link connected to one of said arms and to said crank at one side of the pivoted mount of the crank, a second link connected to the other of said arms and to said crank at the other side of the pivoted mount of the crank, and a third link connected to said crank and to said lever to transmit motion of said lever to said arms via said crank and first and second links.
 3. A rack to support and retain a ladder having side rails and steps on a vehicle during normal movement of the vehicle comprising, in combination an elongated frame; means securing the frame to the vehicle; support means carried by said frame, extending between a ladder loaded on the rack and the vehicle, and engaging at least the rails of the ladder, said support means preventing movement of said ladder in at least one direction; clamp means connected to said frame to secure said ladder to the rack, said clamp means including a first arm and a second arm; mounting means mounting said first and second arms for pivotal movement to a first position in which said arms are spaced from a ladder on said support means, are retracted, and lie between the support means and the vehicle, and to a second position in which each of said arms engages a different step of a ladder on said support means and holds the ladder against the support means; and arm moving means on said frame to simultaneously move said arms from said first positions to said second positions; said arm moving means moving said first arm and second arm pivotally toward each other during movement from said first to said second positions.
 4. A rack to support and retain a ladder having side rails and steps on a vehicle during normal movement of the vehicle comprising, in combination an elongated frame; means securing the frame to the vehicle; support means carried by said frame and engaging at least the rails of a ladder loaded on the rack, said support means preventing movement of said ladder in at least one direction; clamp means connected to said frame to secure said ladder to the rack, said clamp means including a first arm and a second arm; mounting means mounting said first and second arms for pivotal movement to a first position in which said arms are spaced from a ladder on said support means, and to a second position in which each of said arms engages a different step of a ladder on said support means and holds the ladder against the support means; arm moving means on said frame to simultaneously move said arms from said first positions to said second positions; said arm moving means moving said first arm pivotally in one direction, and said second arm pivotally in a direction opposite to said one direction during movement from said first to said second positions; and wherein the steps of the ladder to be carried by the rack are rungs of arcuate curvature; said arms each have an arcuately curved portion spaced from the location where the arms are pivotally mounted; and said arcuately curved portions of said arms resPectively engage spaced apart rungs of the ladder, with said arms in said second position.
 5. A roof rack for a vehicle to support and retain a ladder having side rails and rungs of arcuate curvature on the vehicle during normal travel of the vehicle comprising, in combination an elongated frame comprising spaced apart side members, and cross members extending between and secured to said side members; means securing the frame on the roof of a vehicle; a plurality of resilient support rollers; means mounting said resilient rollers on said frame in coplanar relation for rotation about axes spaced apart longitudinally of said frame, whereby a ladder on said rack engages said rollers and is supported in spaced relation to the roof of the vehicle; clamp means to secure a ladder to said frame, said clamp means being connected to said frame and including a first arm and a second arm, said arms each having an arcuately curved ladder rung engaging portion; mounting means mounting said first and second arms for pivotal movement in opposite directions about spaced apart axes parallel to the length of the rungs of a ladder on the rack, to a first position in which said rung engaging portions are between a ladder on the rack and the roof of the vehicle, and to a second position in which said arms extend between rungs of the ladder and said curved portions each engage a different rung of the ladder and exert force on the rungs to urge the ladder toward the resilient support rollers; lever means; means mounting said lever means on said frame at a location readily accessible for manipulation by a person adjacent the vehicle; and linkage means connecting said lever means and said first and second arms, said lever means being operable, upon manual manipulation, to move said arms toward each other during movement from said first to said second positions.
 6. A rack according to claim 5 wherein said rack further includes lock means to lock said first and second arms in said second position to prevent unauthorized removal of a ladder from said rack.
 7. A rack according to claim 6 wherein said lock means prevents movement of said lever means.
 8. A rack according to claim 4 wherein said support means comprise a plurality of resilient rollers.
 9. A rack according to claim 4 wherein said rack further includes guide rollers having axes of rotation generally normal to the plane of a ladder on the rack, and spaced apart longitudinally of said frame; said guide rollers facilitating the positioning of a ladder on the rack. 